1. Field of the Invention
The present invention relates to the field of secure user interfaces.
This application claims priority to European Application 04253503.9, filed 11 Jun. 2004, the entire content of which is hereby incorporated by reference.
2. Description of the Prior Art
The provision of secure zones within processors, such that a user is able to work with confidential data with some degree of assurance that this data cannot be accessed by an unauthorised person is known. There are a number of different secure systems which each seek to provide protected access to data. One problem with such systems is how to indicate to the user that a display area is trustworthy, i.e. that the processor is operating within a secure zone, such that a user can be confident that the displayed data is data from the secure system and not from the normal space applications and that any data that he enters will not be accessible to others.
One way of addressing this problem is to provide a particular icon, such as a padlock, which can be displayed on a generic screen space during secure operation and thereby provide an indication to the user that the processor is operating within a secure domain. One disadvantage of such a system is that it is not difficult for an application trying to mimic the secure system to display such an icon. Thus, the user could be led to believe that he was operating within a secure state when he was not.
An alternative more secure option would be to use the support of secure hardware to drive a dedicated screen space. A disadvantage with this is that for applications such as mobile phones, the current phone LCD space is of such value that it is not desirable to dedicate any for a particular task such as secure indication.
Another option would be to provide a dedicated external indicator such as an LED that would indicate that the whole display area is in some form of secure mode. This is also felt to be too expensive by the phone manufacturers.